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0.75HP 3-3/16" SL x 3-5/8" OD Impeller 310-3990 0.75HP - Bubbles Supply

0.75HP 3-3/16" SL x 3-5/8" OD Impeller 310-3990

Part #: 310-3990

$39.96
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About this impeller

This genuine Waterway Hi-Flo impeller delivers reliable 0.75HP performance for spa main pumps requiring the 3-3/16" seal length and 3-5/8" outer diameter configuration. Engineered for Waterway pump systems, this OEM replacement part restores optimal water circulation and pressure to keep your spa running smoothly.

Built to Waterway's exacting specifications, this impeller ensures exact fit guaranteed with same-day shipping and our comprehensive 1-year warranty for complete peace of mind. The precision-molded design handles the demanding requirements of 0.75HP applications while maintaining quiet, efficient operation. Before installation, verify your pump's seal length and impeller diameter measurements match the 3-3/16" SL x 3-5/8" OD specifications to ensure proper fitment.

Exact part number

310-3990

Save this for ordering or warranty claims

Also known as / Replaces

This part replaces or is interchangeable with:

  • 0.75HP spa pump impeller
  • 3-3/16 seal length impeller
  • Waterway Hi-Flo impeller

Looking for an older part number? Check our supersession lookup tool

Technical specifications

Horsepower
0.75 HP

Common symptoms this part fixes

If your spa is showing any of these signs, this part is likely your fix:

  • Weak or low water flow from jets
  • Pump runs but water pressure is noticeably reduced
  • Impeller visibly cracked, worn, or broken on inspection
  • Pump cavitating or making grinding/rattling noise
  • Spa jets barely pushing water despite pump running

Not sure if this is your problem? Try our diagnostic centre or .

Before you buy — quick checklist

  • Measure your existing impeller's seal length — must match 3-3/16" (SL) exactly
  • Measure your existing impeller's outer diameter — must match 3-5/8" (OD) exactly
  • Confirm your pump is rated at 0.75HP — this impeller is not interchangeable with 1.0HP or 1.5HP variants
  • Verify your pump is a Waterway Hi-Flo series before ordering
  • Inspect the pump seal and diffuser while the pump is open — they may need replacement at the same time

Reading the checklist now prevents 90% of returns. Worth the 60 seconds.

Install difficulty: Medium — Some experience neededTypically 45–90 minutes

Warranty

1 year manufacturer warranty against defects

Covers manufacturing defects. Does not cover improper installation, normal wear, or accidental damage.

Warranty claims: warranty@bubblessupply.com

Perfect Fit Guarantee

Ordered with our help and the part doesn't fit? Contact us before installation. We'll resolve it with an exchange, replacement recommendation, or return approval.

Learn about our Perfect Fit Guarantee →

Shipping

We ship across the US and Canada. US orders ship from our US warehouse to US customers; Canadian orders ship from our Canadian warehouse to Canadian customers — no cross-border shipping, no surprise duties. In-stock orders placed before 3pm CT ship same day. Standard shipping $9.95 flat rate. Free shipping on orders over $200. Express options available at checkout.

Returns

30-day hassle-free returns on unused parts in original packaging. Contact us before returning to receive your RMA number.

Frequently asked questions

Check the Compatibility section above to confirm fitment for your spa brand and model. If your model is not listed, use our fitment selector at /pages/find-my-part or ask our parts AI for a personalized recommendation.

In-stock orders placed before 3pm CT ship the same day. You will receive tracking information by email as soon as your order ships.

We accept returns within 30 days of delivery for unused items in original packaging. Email returns@bubblessupply.com with your order number to start a return. Installed electrical parts cannot be returned for safety reasons.

Yes, all new parts come with a 1-year warranty against manufacturing defects. Warranty does not cover damage from improper installation or normal wear and tear.

Customer reviews

AI Fitment Assistant

Tell us your spa model and we will confirm this part fits before you buy.

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